An1BnX3n1

An1BnX3n1 is an alphanumeric label that has appeared in a range of theoretical, educational, and data-handling contexts to illustrate labeling schemes and anonymization. It is not a registered chemical name, gene symbol, or database accession, and there is no single, universally accepted definition for the string.

Structure and interpretation: The label combines uppercase letters A, B, and X with digits and lowercase n characters. In example materials, the elements may be interpreted as tokens in a templated pattern, with n serving as a placeholder or repetition marker. Because the meaning of each component is defined by the surrounding context, the same string can have different semantics in different fields.

Uses: In teaching and demonstrations, An1BnX3n1 is used to show how identifiers can be constructed, parsed, or anonymized. It can serve as a test case in regular-expression exercises, data-serialization tasks, or software parsers. In published work, it would typically be accompanied by a definition clarifying its intended meaning.

Relation to formal identifiers: The sequence does not map to InChI, SMILES, PubChem CIDs, GenBank accessions, or DOIs unless specifically defined by the author. Its value lies in illustrating form rather than substance.

See also: identifiers, data labeling, tokenization.